Thank you for your response. DataVirtualization demo which is provided on your website will not work for my scenario.
My problem is i am not having any control on the data which is pushed from thirdparty WCF service.
I am planning to implement the following steps to implement On-Demand scrolling on the grid.
Step1: Get some records lets day (100 records) from the third party service and populate a collection which is tied to the grid (in MVVM)
Step2: When user start scrolling the records and when the grid display last record i need to call the third party WCF service to give me next set of 100 records. (My question is can i bind any property of radgrid which will tell if the grid is displaying last record when user hit the last record).
Note: i am not using code behind so i cannot take advantage of the events which are available.
Since i have only limited set of data in my collection lets say (100 records or 200 records) and these records will be added to the collection based on the need. can i use VirtualQueryableCollectionView. to implement datavirtualization of the existing set records.
In short my datacontext will be a observable collection. Do you have any sample example which explain how to implement datavirtualization using observable collection as datacontext ?